The present invention relates to a machine for making both ice creams and shakes.
As is known, a machine of this type comprises, closed inside a base, a mixing tank connected by a pump to a freezing chamber, and a refrigerant unit consisting of a motor-driven compressor, a condenser and an evaporator associated with the freezing chamber. The front end of the freezing chamber is closed, at a vertical wall of the base, by a door inside which there is a cylindrical compartment. Inside the base there is also an environment, preferably refrigerated, containing a tank of diluting liquid (water or milk or a mixture of water and milk) and containers for flavoring syrups.
Pipes, with pumps inserted between them, connect the diluting liquid tank and the flavoring syrup containers to the cylindrical compartment.
A piston runs inside the cylindrical compartment, with each outward stroke dispensing a dose of ice cream or shake through a dispenser nozzle consisting of an opening made in a plate which closes the lower end of the cylindrical compartment.
The product dispensed consists of ice cream or shake, depending whether or not the cylindrical compartment is connected to the diluting liquid tank by suitable selector means.
In practice, to dispense ice cream, a screw mixer housed in the freezing chamber is activated to feed forward the product contained in the chamber towards the front end.
In this way, the product is fed into the cylindrical compartment in which a screw mixer mixes the product with one or more flavoring syrups, also distributed in the cylindrical compartment by respective pumps.
To dispense shake, the product is mixed with the diluting liquid distributed directly in the cylindrical compartment through the respective positive displacement pump. The positive displacement pump is activated by suitable electronic selector means which feed dosed quantities of diluting liquid.
In this way, the screw mixer mixes the products with any flavoring syrups, to obtain the shake, which is much more liquid than the ice cream.
As already indicated, both the ice cream and the shake are dispensed outside the cylindrical compartment by the action of the piston which pushes the product through the opening made in the lower plate.
The opening usually consists of a opening with a “star-shaped” extension to give the ice cream forced out through the opening an outline that has an attractive appearance.
However, it should be noticed that the particular shape of the opening, although functional for ice creams, has significant disadvantages for dispensing a shake.
A shake (significantly more liquid than ice cream) is dispensed in an uneven manner due to the breadth of the opening and the variation in its cross-section.
Said variation in the cross-section leads to the formation of turbulence in the flow of shake coming out of the opening, with the consequent formation of splashes which, detaching from the flow falling towards a respective container below the opening, are projected outside the container, affecting the zones surrounding the machine.
To overcome this disadvantage openings are made having a narrow cross-section for the passage of the product, to contain the flow of shake and limit the dispersion of splashes.
However, even in this situation there are significant disadvantages, because the flow of shake is still uneven and ice cream is not dispensed in the optimum way. Given the density of the ice cream, the time taken to dispense it through a noticeably smaller cross-section for its passage is longer.